Karen has plans to go to a movie and already has a $10 nonrefundable, nonexchangeable, and nontransferable ticket. Now Carlos, whom Karen has wanted to date for a long time, asks her to a concert. Karen would prefer to go to the concert with Carlos and forgo the movie, but she doesn't want to waste the $10 she spent on the movie ticket. From the perspective of an economist, if Karen decides to go to the concert with Carlos, what has she just done? Incorrectly allowed a sunk cost to influence her decision Made a choice that was not optimal Correctly ignored a sunk cost